JnyJny

This worked for me instead of the "copy things around" fix: Once the KSP_osx folder unpacked in my Downloads folder, I ran the following command in a Terminal window: $ xattr -dr com.apple.quarantine ~/Downloads/KSP_osx So replace "~/Downloads/KSP_osx" with the path to your KSP folder and remove the "quarantine" attribute which is causing the hang.